1. Field of the Invention
The present invention is related to the fields of polymer and fine chemical engineering, more particularly, the present invention is related to an one component self-crosslinking reactive siloxane-terminated polypropylene oxide emulsion and a process for preparing the same.
2. Brief Description of Related Technology
As the base polymer for sealing materials, in recent years the reactive siloxane-terminated polypropylene oxide (SPPO) was developed quickly. All the companies from Germany such as Henkel and Degussa as well as the companies from USA such as Witco and Crompton etc develop sealing gums using SPPO as the base polymer, and the application of SPPO has been broadened from the earliest architectural field to others such as automotive field etc. However, nationwidely, the development with regard to SPPO is relatively slow, there are less reports about R&D and the relative patents can hardly be found.
As an important base polymer, waterborne SPPO not only will reduce the environmental pollution, but also can reduce the cost and simplify the production procedure with addition of various coagents, thus its application can be broadened from present architectural and automotive fields to domestic fields such as home furnishing and decoration etc.
However, SPPO molecular is with extremely strong hydrophobicity and comprises reactive terminal silanyloxy groups, which are extremely hydrosensitive and hydrolytic crosslinkable, thus hardly being waterborne, and presently no reports about waterborne SPPO can be found.
Thus, the preparation of waterborne SPPO emulsion with excellent properties can broaden the applications of SPPO greatly and is very important in practices and business.
Direct emulsification and phase inversion emulsification can emulsify polymers into waterborne emulsions without changing the molecular structures. Of which the direct emulsification generally needs a lot of surfactants and has to be stirred strongly for a long time, and only some polymers with special properties can be emulsified directly, so the application is limited. In contrary to the direct emulsification, the phase inversion emulsification can emulsify many polymers into waterborne emulsion directly without strong stirring, and the obtained emulsion is with small latex particle size and excellent stability.